Why does ones sense of rationality at times become overwritten because of a particular individual that you care about?

I mean if a girl I liked was a mass murderer I'd play it off as one of her adorable quirks that makes her unique. I'm sure I'm not the only person that has this (Well perhaps not to the extremes of the abovementioned example )

How about smaller things...like long distance relationships. I mean the ones that you know won't work out in the long run, but you really want to, and become something big before being ruined.

Why do people put themselves in these situations? I know they don't purposely do it, and try to work around it but there has to be points throughout where they realise it just can't happen but still persist.

I was thinking about this earlier, I hope everyone can understand what I mean here and anything you want to put is welcomed as I'm interested in what people think about this.

Humankind challenges itself constantly...Even if it's getting off the sofa to get another beer!

People want to make things work...Want to make things happen.

To not desire more would be un-human!

'you're gonna have to face it, you're addicted to love'

That song just about sums it up.